I have seen examples of 3D printing in the past. It required a multi-thousand dollar printer. But at the time it was pointed out that the original CD burners were also in the same ballpark in cost when taking inflation into account.
Now there is a demonstration on line of how Disney could use the same type of printing to print three dimensional optical devices. An example is below, but you will need to go to Engadget’s site to see a video on how this printed material could be put to use. At least at first.
See the full article here: http://www.engadget.com/2012/10/05/seeing-is-believing-disney-crafts-3d-printed-optics-video